During the partition IPL, the partition terminal was associated to the console serial port. During partition shutdown, the unassociation of the partition terminal to the console serial port failed. There may be a service processor problem. Check for firmware updates and install them. If there are no firmware updates available, look for and correct errors with SRCs of the form B1xxxxxx in the Serviceable Event View. If that does not resolve the problem, contact your next level of support.